1 | /* Copyright (C) 2002-2024 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <pthread.h> |
20 | #include <stdint.h> |
21 | #include <stdio.h> |
22 | #include <stdlib.h> |
23 | #include <string.h> |
24 | #include <unistd.h> |
25 | #include <sys/mman.h> |
26 | #include <sys/wait.h> |
27 | |
28 | |
29 | static int |
30 | do_test (void) |
31 | { |
32 | size_t ps = sysconf (_SC_PAGESIZE); |
33 | char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX" ; |
34 | char data[ps]; |
35 | void *mem; |
36 | int fd; |
37 | pthread_mutex_t *m; |
38 | pthread_mutexattr_t ma; |
39 | pthread_rwlock_t *r; |
40 | pthread_rwlockattr_t ra; |
41 | pid_t pid; |
42 | int status = 0; |
43 | |
44 | fd = mkstemp (template: tmpfname); |
45 | if (fd == -1) |
46 | { |
47 | printf (format: "cannot open temporary file: %m\n" ); |
48 | return 1; |
49 | } |
50 | |
51 | /* Make sure it is always removed. */ |
52 | unlink (name: tmpfname); |
53 | |
54 | /* Create one page of data. */ |
55 | memset (data, '\0', ps); |
56 | |
57 | /* Write the data to the file. */ |
58 | if (write (fd, data, ps) != (ssize_t) ps) |
59 | { |
60 | puts (s: "short write" ); |
61 | return 1; |
62 | } |
63 | |
64 | mem = mmap (NULL, len: ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd: fd, offset: 0); |
65 | if (mem == MAP_FAILED) |
66 | { |
67 | printf (format: "mmap failed: %m\n" ); |
68 | return 1; |
69 | } |
70 | |
71 | r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t)) |
72 | & ~(__alignof (pthread_rwlock_t) - 1)); |
73 | /* The following assumes alignment for a mutex is at least as high |
74 | as that for a rwlock. Which is true in our case. */ |
75 | m = (pthread_mutex_t *) (r + 1); |
76 | |
77 | if (pthread_rwlockattr_init (attr: &ra) != 0) |
78 | { |
79 | puts (s: "rwlockattr_init failed" ); |
80 | return 1; |
81 | } |
82 | |
83 | if (pthread_rwlockattr_setpshared (attr: &ra, PTHREAD_PROCESS_SHARED) != 0) |
84 | { |
85 | puts (s: "rwlockattr_setpshared failed" ); |
86 | return 1; |
87 | } |
88 | |
89 | if (pthread_rwlock_init (rwlock: r, attr: &ra) != 0) |
90 | { |
91 | puts (s: "rwlock_init failed" ); |
92 | return 1; |
93 | } |
94 | |
95 | if (pthread_mutexattr_init (attr: &ma) != 0) |
96 | { |
97 | puts (s: "rwlockattr_init failed" ); |
98 | return 1; |
99 | } |
100 | |
101 | if (pthread_mutexattr_setpshared (attr: &ma, PTHREAD_PROCESS_SHARED) != 0) |
102 | { |
103 | puts (s: "mutexattr_setpshared failed" ); |
104 | return 1; |
105 | } |
106 | |
107 | if (pthread_mutex_init (mutex: m, mutexattr: &ma) != 0) |
108 | { |
109 | puts (s: "mutex_init failed" ); |
110 | return 1; |
111 | } |
112 | |
113 | /* Lock the mutex. */ |
114 | if (pthread_mutex_lock (mutex: m) != 0) |
115 | { |
116 | puts (s: "mutex_lock failed" ); |
117 | return 1; |
118 | } |
119 | |
120 | puts (s: "going to fork now" ); |
121 | pid = fork (); |
122 | if (pid == -1) |
123 | { |
124 | puts (s: "fork failed" ); |
125 | return 1; |
126 | } |
127 | else if (pid == 0) |
128 | { |
129 | /* Lock the mutex. */ |
130 | if (pthread_mutex_lock (mutex: m) != 0) |
131 | { |
132 | puts (s: "child: mutex_lock failed" ); |
133 | return 1; |
134 | } |
135 | |
136 | /* Try to get the rwlock. */ |
137 | if (pthread_rwlock_trywrlock (rwlock: r) == 0) |
138 | { |
139 | puts (s: "rwlock_trywrlock succeeded" ); |
140 | return 1; |
141 | } |
142 | |
143 | /* Try again. */ |
144 | struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 }; |
145 | int e = pthread_rwlock_timedwrlock (rwlock: r, abstime: &ts); |
146 | if (e == 0) |
147 | { |
148 | puts (s: "rwlock_timedwrlock succeeded" ); |
149 | return 1; |
150 | } |
151 | if (e != ETIMEDOUT) |
152 | { |
153 | puts (s: "rwlock_timedwrlock didn't return ETIMEDOUT" ); |
154 | status = 1; |
155 | } |
156 | |
157 | if (pthread_rwlock_tryrdlock (rwlock: r) == 0) |
158 | { |
159 | puts (s: "rwlock_tryrdlock succeeded" ); |
160 | return 1; |
161 | } |
162 | |
163 | e = pthread_rwlock_timedrdlock (rwlock: r, abstime: &ts); |
164 | if (e == 0) |
165 | { |
166 | puts (s: "rwlock_timedrdlock succeeded" ); |
167 | return 1; |
168 | } |
169 | if (e != ETIMEDOUT) |
170 | { |
171 | puts (s: "rwlock_timedrdlock didn't return ETIMEDOUT" ); |
172 | status = 1; |
173 | } |
174 | } |
175 | else |
176 | { |
177 | /* Lock the rwlock for writing. */ |
178 | if (pthread_rwlock_wrlock (rwlock: r) != 0) |
179 | { |
180 | puts (s: "rwlock_wrlock failed" ); |
181 | kill (pid: pid, SIGTERM); |
182 | return 1; |
183 | } |
184 | |
185 | /* Allow the child to run. */ |
186 | if (pthread_mutex_unlock (mutex: m) != 0) |
187 | { |
188 | puts (s: "mutex_unlock failed" ); |
189 | kill (pid: pid, SIGTERM); |
190 | return 1; |
191 | } |
192 | |
193 | /* Just wait for the child. */ |
194 | if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid) |
195 | { |
196 | puts (s: "waitpid failed" ); |
197 | kill (pid: pid, SIGTERM); |
198 | return 1; |
199 | } |
200 | } |
201 | |
202 | return status; |
203 | } |
204 | |
205 | #define TEST_FUNCTION do_test () |
206 | #include "../test-skeleton.c" |
207 | |